Mitha Hardianni,2013 Problem Based Learning To Enhance Students’ Critical Thinking Skills And Concept Comprehension In
Pollution Concept Universitas Pendidikan Indonesia
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Table 3.1 One group pre test and post test design Pre test
Treatment Post test
O
1
X O
2
O
1
= Pre test of students concept comprehension and critical thinking skill. X
= Problem Based Learning model O
2 =
Post test of students concept comprehension and critical thinking skill.
Steps to implement the research first time students be given pre test O
1
to know students‟ prior concept comprehension and critical thinking skill then gave
treatmentX which used Problem Based Learning approach and the last gave post
test O
2
to students. Thus, it can be obtained the differences between pretest and posttest which assumed as the effect of treatment.
D. Operational Definition
To avoid misconception in this research, so there is explanation about the terms that are used in this research, as follow:
1. Problem Based Learning
Problem Based Learning is approach that use real life problem in learning process. In this research teacher will give problem to students. Students work in
group to solve problem to make students become an active learner as well as problem solver. In this research use five steps to implement Problem Based
Learning such as ideas, know facts, learning issues, action plan and evaluate products and process.
Mitha Hardianni,2013 Problem Based Learning To Enhance Students’ Critical Thinking Skills And Concept Comprehension In
Pollution Concept Universitas Pendidikan Indonesia
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2. Concept comprehension
Concept comprehension in this research based on cognitive domain of Bloom‟s taxonomy new revision. The aspects that use in this research are remembering
aspect C1, understanding aspect C2, analyzing aspect C4 and evaluating aspect C5.
3. Critical thinking skill
According to Ennis critical thinking is process to make decision based on what believe and what to do. There are six aspects that include in critical thinking
skills but in this research just take five aspect of critical thinking skills as indicator because the sixth aspect only asses students behavior. So to make test
item for students‟ critical thinking researcher use five indicators such as clarification, decision, inference, advanced clarification, supposition and
integration. The result of students‟ test will be scored by scoring guide.
E. Research Instrument
To collect the data there are some instrument that be needed: 1.
Students‟ concept comprehension test To measure Students‟ concept comprehension test item that be used is multiple
choice. Researcher made 34 multiple choice test items then would be
eliminated based on analysis result of trial instrument. Total question number that be used for pre test and post test are 15 questions of multiple choice which
each multiple-choice item is given a numeric value of one for correct answer and zero for incorrect. Blue print for this multiple choice is made based on
cognitive aspects in Bloom‟s taxonomy can be seen on appendix C.1.
Mitha Hardianni,2013 Problem Based Learning To Enhance Students’ Critical Thinking Skills And Concept Comprehension In
Pollution Concept Universitas Pendidikan Indonesia
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2. Students‟ critical thinking skills test
To measure students‟ critical thinking test item that be used is essay. Researcher choose essay test item because more efficient to asses critical
thinking. The number of question that be used are five questions which used range score from three until zero. Critical thinking skills indicator is used to
make blueprint of critical thinking skills test as shown on appendix C.3.
3. Observation sheet
There are two kinds of observation sheets that will be used in this research such as:
a. Teacher‟s observation sheet
This observation sheet is advantageous to investigate whether process of Problem Based Learning run well or not. This observation sheet can be seen
on appendix C.5 b.
Students‟ observation sheet This observation sheet is advantageous
to investigate students‟ activities during learning process is appropriate or not with problem Based Learning.
This observation sheet can be seen on appendix C.6
4. Questionnaire of students‟ response
This questionnaire is used to know students‟ response toward Problem based
Learning process. Students must fulfil the questionnaire by give mark on scale number which presents their agreement for option “YES” and disagreement for
option “NO”. The interview guideline used to know teacher point of view as additional information about learning process through Problem Based Learning
and students‟ critical thinking skill.
Mitha Hardianni,2013 Problem Based Learning To Enhance Students’ Critical Thinking Skills And Concept Comprehension In
Pollution Concept Universitas Pendidikan Indonesia
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5. Teacher interview
The interview carried with biology teachers who teach in class that were used as research subjects. This interview is intended to find out teachers opinions
toward Problem Based learning.
F. Validation of Instruments
